Calculate This Finance · Tip
Module · Finance

Tip
Calculator

Tip math and bill splitting that doesn't make you do mental arithmetic at the table. Custom percentages, round-up options, tip on pre- or post-tax.

See the math behind this calculator
Service standard
15 – 20%

Exceptional service
22 – 25%

Tip basis
Pre-tax preferred
The bill
Tip percentage
Split
Per person $0.00
Tip amount $0.00
Grand total $0.00
Effective tip rate -
Tip per person $0.00

The math

Tip is straightforward arithmetic: multiply the bill by a percentage, then add it back to the total. The only real questions are which number to multiply, and how to split it.

tip = base × (percent ÷ 100)
per_person = (base + tip) ÷ people

Where "base" is either the total bill or the pre-tax subtotal, depending on how you tip. The difference between the two methods is usually about 1-2% of the total - a few dollars on a $100 bill.

Frequently asked

Should I tip on tax?

Etiquette says no - tip is for the service, not the government. Math says it barely matters. If you're tipping 20% on a $100 bill with $8 tax, you'd give $20 on pre-tax or $21.60 on total. The server probably won't notice or care.

What about automatic gratuity?

Large parties often get 18-20% added automatically. Always check the bill before adding more. Many people see "service charge" and tip again out of habit. If the auto-grat is on, you've already tipped.

Is tipping really required?

In the US, restaurant servers are typically paid below minimum wage with the expectation that tips will make up the difference. Skipping a tip on standard service essentially asks the server to pay for the privilege of waiting on you. If you object to the tipping system, the move is to support legislation that pays service workers a real wage - not to stiff your server.

Show the working

The order of operations matters here, particularly when you round up. This is the sequence the page follows. If any of it looks wrong, it might be - tell us what we got wrong.

Tip basis pre-tax → basis = bill − tax post-tax → basis = bill
Tip tip = basis × (percent ÷ 100)
Total, then rounding total = bill + tip round up to $1 → total = ceil(total) round up to $5 → total = ceil(total ÷ 5) × 5
Tip recomputed after rounding tip = total − bill
Split and effective rate per person = total ÷ people tip per person = tip ÷ people effective rate = tip ÷ bill × 100

Note the tip is recalculated after rounding rather than before. Rounding the total up and keeping the original tip figure would leave the two not adding up, which is the bug in most tip calculators that offer rounding.